Method for adjusting a directional characteristic and a hearing apparatus

Abstract

The aim is to improve the adjustment of the directional characteristic of a hearing apparatus, and in particular of a hearing aid. A method is therefore provided in which a microphone signal having a plurality of frequency bands is derived from an input sound being obtained by a microphone system containing at least two microphones. A characteristic of the microphone signal is then determined, for example the level. The directional characteristic of the microphone system is adjusted in dependence on the determined characteristic of the microphone signal. In order to adjust the directional characteristic, two or more frequency bands are combined in dependence on the determined characteristic of the microphone signal. Alternatively, one of the microphones can also be attenuated, thus deliberately reducing the directionality of the directional microphone.

1 . A method for adjusting a directional characteristic of a hearing apparatus, which comprises the steps of:
 obtaining a microphone signal having a plurality of frequency bands from an input sound by means of a microphone system having at least two microphones;   determining a characteristic of the microphone signal; and   adjusting a directional characteristic of the microphone system in dependence on the characteristic of the microphone signal, for adjusting the directional characteristic, at least two of the frequency bands are combined in dependence on the characteristic of the microphone signal to form a broader frequency band being combined frequency bands, and a common directional characteristic is in this way provided for the combined frequency bands, the common directional characteristic being slurred in comparison to directional characteristics for the at least two frequency bands, such that a directivity of the common directional characteristic is reduced.   
     
     
         2 . The method according to  claim 1 , wherein the characteristic of the microphone signal includes its level. 
     
     
         3 . The method according to  claim 2 , which further comprises increasing a directionality of the microphone system as the level increases. 
     
     
         4 . The method according to  claim 1 , wherein the characteristic of the microphone signal characterizes at least one predetermined acoustic situations. 
     
     
         5 . The method according to  claim 1 , wherein a number of the combined frequency bands is varied manually, and a current number is learnt by the hearing apparatus, together with a current characteristic of the microphone signal for later automatic adjustment. 
     
     
         6 . The method according to  claim 1 , wherein switching takes place from a static operating mode, in which a number of the combined frequency bands is fixed, to an adaptive operating mode, in which the number of combined frequency bands is automatically matched to a current situation. 
     
     
         7 . A hearing apparatus, comprising:
 a microphone system containing at least two microphones for obtaining a microphone signal having a plurality of frequency bands, from an input sound;   an analysis device for determining a characteristic of the microphone signal and coupled to said microphone system; and   a processing device for adjusting a directional characteristic of said microphone system in dependence on the characteristic of the microphone signal, and while the directional characteristic is being adjusted, said processing device can combine at least two of the frequency bands in dependence on the characteristic of the microphone signal to form a broader frequency band being combined frequency bands, and can in this way provide a common directional characteristic for the combined frequency bands, the common directional characteristic being slurred in comparison to directional characteristics for the at least two frequency bands, such that a directivity of the common directional characteristic is reduced.   
     
     
         8 . A method for adjusting a directional characteristic of a hearing apparatus, which comprises the steps of:
 obtaining a microphone signal from an input sound by means of a microphone system having at least two microphones;   determining a characteristic of the microphone signal; and   adjusting the directional characteristic of the microphone system in dependence on the characteristic of the microphone signal, in order to adjust the directional characteristic, the adjusting step performing one of:
 attenuating one of the two microphones in dependence on the characteristic of the microphone signal resulting in a directivity of the directional characteristic being reduced; and 
 mismatching both of the microphones to one another in dependence on the characteristic of the microphone signal resulting in the directivity of the directional characteristic being reduced. 
   
     
     
         9 . The method according to  claim 8 , which further comprises carrying out the attenuating or the mismatching in dependence on an instantaneous gain in the hearing apparatus. 
     
     
         10 . The method according to  claim 8 , wherein the microphone system has a front microphone and a rear microphone with respect to a predetermined wearing position of the hearing apparatus, and the rear microphone is attenuated. 
     
     
         11 . A hearing apparatus, comprising:
 a microphone system containing at least two microphones for obtaining a microphone signal from an input sound;   an analysis device for determining a characteristic of the microphone signal and coupled to said microphone system; and   a processing device for adjusting a directional characteristic of said microphone system in dependence on the characteristic of the microphone signal, and while adjusting the directional characteristic, said processing device can attenuate one of said two microphones in dependence on the characteristic of the microphone signal, or both of said microphones are mismatched to one another in dependence on the characteristic of the microphone signal, so as to reduce a directivity of the directional characteristic.